Network explorer: Serve the static bundle for all routes not handled by the API

[raykyri]

Inside the network explorer (both chat-explorer and common-explorer), the client router automatically changes the URL to /actions when landing on the network explorer page. Refreshing then gives you a 404 because only the root is served by the static URL handler.

We should make it so that express serves the static bundle using a catch-all. I tried to get this to work using the default express static middleware but it kept serving assets with the wrong MIME type...